Black families vitamin d? Or diet? Or both?

My father ( black East African) has 9 brothers and 1 sister. He in turn had 6 boys and 1 girl ( me). We all moved to Europe 30 years ago. My brothers grew up here, and they have all struggled to have sons. All six are married boy/girl numbers for each are:
Brother 1) 1girl 2 boys
2. 1 girl 1 boy
3. 2 girls 0 boy
4. 4 girls 0 boys
6. 3 girls 0 boys
So out of 14 grandkids there’s 3 boys. My brother with the 2 boys lives in Africa and his children were conceived there. My second brother with the 1 boy, came to Europe at an older age to the others.

There is an identical pattern with my paternal male cousins. The ones in colder climates have far fewer sons then our cousins near the equator.

As for me, my husbands dad had 6 brothers no sisters. He in turn had 7 boys and 2 daughters. My husbands 2 sisters each have 2 daughters.

So far me and my husband have 1 daughter.

I never thought about baby gender or sways till I realised there are almost no boys born to our families and other families from our region in Africa, despite having lots of brothers ( they say men with many brothers tend to have boys).

I am now wondering if lack of vitamin D or some other component found in the tropics is involved in boy gender sway.
Does anyone else have experience with something like this in their families? Besides vitamin D what else might it be? Maybe pollution? High carb diet? ( my dads generation ate high fat medium protein low carb diet which is basically keto though perhaps not in full ketosis . But I’ve been reading the keto diet makes the body acidic and that sways girl).

If diet this also contradicts current thinking that more calories=boy. As back then everyone was pretty
thin, though that doesn’t = nutrient deprived.

For reasons we do not know, there are more girls conceived both to people of Sub-Saharan African descent and to people (regardless of ethnicity) in equatorial countries. We don't know why (and this is obviously not at all universal, as your situation demonstrates)

As you can see in your own family makeup it doesn't seem to be genetic (as there are quite a lot of families that go from being very heavy in one gender, to very heavy in another, over the course of a generation)

I could speculate about a lot of different reasons why this might be - it may be there are lifestyle and diet factors or it may have been just sheer luck. My family went from having 5 boys and 1 girl to 7 boys and 6 girls over the course of just a couple years.

But that having been said yes I do recommend every blue swayer take 1000 IU or even more if advised by a doctor of Vitamin D and we've had good luck with that.

The "acid alkaline" theory has been debunked both overall and for gender swaying. Keto diets can be for some people, nutrient deficient and may sway pink for them, but a keto diet done carefully with a balanced diet with a wide variety of nutrients would tend to sway boy.

I’m actually really curious to know how the study on less baby girls near equator was conducted, because anecdotally that couldn’t be further from the truth.

Regardless, what really surprises (and kinda worries me) is not a slight-to-moderate skew to girls but a very severe skew. To have 3 sons out of 14 grand kids or 15 if you include mine. That’s like 80% girls 20% boys.
My mother in law was telling me about knowing 17 new babies in her town being born last year, to people from our region. Of the 17 new births that she knew there was 1 boy. The same story everywhere you turn. All my girlfriends have nothing but daughters. If this was happening to a larger more visible population the science community would be up in arms, as it stands I can find virtually no information on why this is happening, or even any researchers interested in finding out.

Here's the study https://www.independent.co.uk/news/s...n-1658981.html

When scientists study this topic they are looking for very small variations in the gender ratio. It's not a huge difference, just between 102 boys for every 100 girls vs. 106 boys for every 100 girls. Not something we can really see with our naked eye. We do know that sometimes there are temporary and dramatic shifts in gender ratio for reasons that no one knows just yet. I agree very few researchers are interested in studying gender ratio.

Thanks for the link x